Columns

You can use the getColumns method of the DatabaseMetaData interface to retrieve column information. You can restrict the results by the table name. The code example below retrieves the column names for the SampleTable_1 table:

String connectionString = "jdbc:parquet:URI=C:\folder\table.parquet;";

Connection conn = DriverManager.getConnection(connectionString);
DatabaseMetaData table_meta = conn.getMetaData();
ResultSet rs = table_meta.getColumns(null,null,"SampleTable_1", null);
while(rs.next()){
  System.out.println(rs.getString("COLUMN_NAME")); 
}

The getColumns method returns the following columns:


Column Name	Data Type	Description
TABLE_CAT	String	The database name.
TABLE_SCHEM	String	The table schema.
TABLE_NAME	String	The table name.
COLUMN_NAME	String	The column name.
DATA_TYPE	int	The data type identified by the value of a constant defined in java.sql.Types.
TYPE_NAME	String	The data type name used by the driver.
COLUMN_SIZE	int	The length in characters of the column or the numeric precision.
BUFFER_LENGTH	int	The buffer length.
DECIMAL_DIGITS	int	The column scale or number of digits to the right of the decimal point.
NUM_PREC_RADIX	int	The radix, or base.
NULLABLE	int	Whether the column can contain null as defined by the following JDBC DatabaseMetaData constants: columnNoNulls (0) or columnNullable (1).
REMARKS	String	The column description.
COLUMN_DEF	String	The default value for the column.
SQL_DATA_TYPE	int	Reserved by the specification.
SQL_DATETIME_SUB	int	Reserved by the specification.
CHAR_OCTET_LENGTH	int	The maximum length of binary and character-based columns.
ORDINAL_POSITION	int	The column index, starting at 1.
IS_NULLABLE	String	Whether a null value is allowed: YES or NO.
SCOPE_CATALOG	String	The table catalog that is the scope of a reference attribute.
SCOPE_SCHEMA	String	The table schema that is the scope of a reference attribute.
SCOPE_TABLE	String	The table name that is the scope of a reference attribute.
SOURCE_DATA_TYPE	int	The source type of a distinct type. Or, a user-generated Ref type. If DATA_TYPE is not DISTINCT, this value is null. If a user-generated Ref, this value is null.
IS_AUTOINCREMENT	String	Whether the column value is assigned by Parquet in fixed increments.
IS_GENERATEDCOLUMN	String	Whether the column is generated: YES or NO.

JDBC Driver for Parquet

Columns